Baby Boomers need an even higher wealth-to-income ratio than their parents had if they want to live securely in retirement, according to a research brief by the Center for Retirement Research at Boston College. That's because of an increased life expectancy, the shift to 401(k) plans, higher health care costs and lower real interest rates.

The report examined the wealth-to-income ratios from 1983 through 2010, information which was gleaned through the Survey of Consumer Finances (SCF), the Federal Reserve's comprehensive triennial survey of household wealth in the United States. The notion is that the wealth-to-income ratio is a good proxy for the extent to which people can replace their pre-retirement earnings in retirement.

The brief concluded that the stable wealth-to-income ratio recorded between 1983 and 2007 should "never have been a source of comfort. The world has changed in important ways that all require more wealth to sustain living standards in retirement," according to Alicia H. Munnell, the brief's author.